package com.yyk.springservicetwo.annotations;

import com.alibaba.fastjson.JSON;
import com.yyk.config.commonService.enumeration.HttpStatusEnum;
import com.yyk.config.commonService.response.YYKCloudResponse;
import org.redisson.api.RAtomicLong;
import org.redisson.api.RLock;
import org.redisson.api.RedissonClient;
import org.springframework.beans.factory.annotation.Autowired;
import org.springframework.stereotype.Component;
import org.springframework.web.method.HandlerMethod;
import org.springframework.web.servlet.handler.HandlerInterceptorAdapter;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.OutputStream;
import java.util.concurrent.TimeUnit;

/**
 * @author ljp
 * @CLASSNAME FangshuaInterceptor
 * @date 2021/2/3 11:21
 * @description：
 */
@Component
public class FangshuaInterceptor extends HandlerInterceptorAdapter {

    @Autowired
    private RedissonClient redissonClient;

    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {

        //判断请求是否属于方法的请求
        if (handler instanceof HandlerMethod) {

            HandlerMethod hm = (HandlerMethod) handler;

            //获取方法中的注解,看是否有该注解
            AccessLimit accessLimit = hm.getMethodAnnotation(AccessLimit.class);
            if (accessLimit == null) {
                return true;
            }
            int seconds = accessLimit.seconds();
            int maxCount = accessLimit.maxCount();
            boolean login = accessLimit.needLogin();
            String key = request.getRequestURI();
            //如果需要登录
            if (login) {
                //获取登录的session进行判断
                //.....
                key += "" + "1";  //这里假设用户是1,项目中是动态获取的userId
            }

            //从redis中获取用户访问的次数
            RLock lock = redissonClient.getLock(key);
            try {
                boolean res = lock.tryLock(seconds, TimeUnit.SECONDS);
                RAtomicLong atomicLong = redissonClient.getAtomicLong(key);
                if (atomicLong == null) {
                    //第一次访问
                    atomicLong.set(1);
                } else if (atomicLong.get() < maxCount) {
                    //加1
                    atomicLong.incrementAndGet();
                } else {
                    //超出访问次数
                    render(response, HttpStatusEnum.HTTP_REQUEST_FREQUENT.getDesc()); //这里的CodeMsg是一个返回参数
                    return false;
                }
            } catch (Exception e) {
                e.printStackTrace();
            } finally {
                lock.unlock();
            }
        }

        return true;
    }

    private void render(HttpServletResponse response, String cm) throws Exception {
        response.setContentType("application/json;charset=UTF-8");
        OutputStream out = response.getOutputStream();
        String str = JSON.toJSONString(YYKCloudResponse.error(cm));
        out.write(str.getBytes("UTF-8"));
        out.flush();
        out.close();
    }
}
